Investigation of multi-metal catalysts for stable hydrogen production via urea electrolysis

It has been shown that urea electrolysis is a viable method for wastewater remediation and simultaneous production of valuable hydrogen. Inexpensive nickel catalyst is optimal for the oxidation of urea in alkaline media but improvements are needed to minimize surface blockage and increase current density. Multi-metal catalysts were investigated by depositing platinum group metals on a nickel substrate. Rhodium and nickel proved synergistic to reduce surface blockage and increase catalyst stability. Rh-Ni electrodes reduced the overpotential for the electro-oxidation of urea and improved the current density by a factor of 200 compared to a Ni catalyst.

▶ Synergistic effect of multi-metal catalysts towards the oxidation of urea in alkaline media was demonstrated. ▶ Continuous hydrogen production based on the electrolysis of urea. ▶ Significant increase in the current density of the urea electrolytic cell achieved (200% increase when compared to the literature).